Abstract—It has been 10 years since CRISPR/Cas technology was applied to edit the genomes of various organisms. Its ability to produce a double-strand break in a DNA region specified by the researcher started a revolution in bioengineering. Later, the Base Editing (BE) method was developed. BE is performed via the formation of single-strand breaks by the mutant form of Cas nuclease (nickase), fused with deaminases and other enzymes. It can be used to promote A \( \leftrightarrow \) G and C \( \leftrightarrow \) T transitions, and a C → G transversion. Just over 3 years ago, a new Prime Editing (PE) variant of CRISPR/Cas was invented. Unlike BE, in PE the nickase is fused with reverse transcriptase, capable of building a new DNA chain using the pegRNA template. The pegRNA consists of an elongated guide RNA with an extra sequence at the 3'-end. Prime editing makes it possible to insert the desired mutations into this extra sequence and to carry out any substitutions and indels of bases without the use of special donor DNA. To date, a number of PE variants have been proposed; they are briefly considered in this review with an emphasis on prime editing of plant genomes. Some attention is also paid to pegRNA design programs, as well as evaluation of the efficiency of the editing. Such a variety of PE techniques is due to the opportunities of high-precision introduction of desired changes with a rather low frequency of off-target mutations in the genomes of various organisms. The relatively low efficiency of prime editing inspires researchers to offer new approaches. There is hope that further development of the technology will improve PE enough to take its rightful place among the genome targeting methods that are suitable for any organisms, and will have a positive impact on the agricultural sector, industrial biotechnologies, and medicine.

摘要：CRISPR/Cas技术应用于多种生物体基因组编辑已有10年的历史。它能够在研究人员指定的 DNA 区域产生双链断裂，引发了生物工程领域的一场革命。后来又发展了碱基编辑（BE）方法。BE 是通过与脱氨酶和其他酶融合的 Cas 核酸酶（切口酶）突变体形成单链断裂来进行的。它可用于促进 A \( \leftrightarrow \) G 和 C \( \leftrightarrow \) T 跃迁，以及 C → G 颠换。就在三年多前，发明了 CRISPR/Cas 的新 Prime Editing (PE) 变体。与 BE 不同，在 PE 中，切口酶与逆转录酶融合，能够使用 pegRNA 模板构建新的 DNA 链。pegRNA 由一个细长的引导 RNA 组成，其 3' 端有一个额外的序列。Prime 编辑可以将所需的突变插入到这个额外的序列中，并在不使用特殊供体 DNA 的情况下进行碱基的任何替换和插入。迄今为止，已经提出了多种 PE 变体；本综述简要考虑了它们，重点是植物基因组的主要编辑。pegRNA 设计程序以及编辑效率的评估也受到了一些关注。如此多样化的 PE 技术是由于各种生物体基因组中脱靶突变频率相当低的情况下，有机会高精度引入所需的变化。质数编辑相对较低的效率激励研究人员提供新的方法。希望该技术的进一步发展能够充分改进 PE，使其在适合任何生物体的基因组靶向方法中占据应有的位置，并将对农业部门、工业生物技术和医学产生积极影响。